More attention to attention? An eye-tracking investigation of selection of perceptual attributes during a task switch

This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.Switching tasks prolongs response times, an effect reduced but not eliminated by active preparation. To explore the role of attentional selection of the relevant stimulus attribute in these task-switch costs, we measured eye fixations in participants cued to identify either a face or a letter displayed on its forehead. With only 200 ms between cue and stimulus onsets, the eyes fixated the currently relevant region of the stimulus less and the irrelevant region more on switch than on repeat trials, at stimulus onset and for 500 ms thereafter, in a pattern suggestive of delayed orientation of attention to the relevant region on switch trials. With 800 ms to prepare, both switch costs and inappropriate fixations were reduced, but on switch trials participants still tended (relative to repeat trials) to fixate the now-irrelevant region more at stimulus onset and to maintain fixation on, or refixate, the irrelevant region more during the next 500 ms. The size of this attentional persistence was associated with differences in performance costs between and within participants. We suggest that reorientation of attention is an important, albeit somewhat neglected and controversial, component of advance task-set reconfiguration and that the task-set inertia (or reactivation) to which many attribute the residual task-switch cost seen after preparation includes inertia in (or reactivation of) attentional parameters

Learning in the absence of overt practice : a novel (previously unseen) stimulus can trigger retrieval of an unpracticed response

Skilled performance is traditionally thought to develop via overt practice. Recent research has demonstrated that merely instructed stimulus-response (S-R) bindings can influence later performance and readily transfer across response modalities. In the present study, we extended this to include instructed category-response (C-R) associations. That is, we investigated whether merely instructed C-R bindings can trigger an unpracticed response (in a different modality) on perception of a novel (previously unseen) stimulus. In a learning-test design, participants had to classify stimuli by comparing them to perceptual category templates (Experiment 1) or semantic category descriptions (Experiment 2) presented prior to each block. During learning blocks, participants had to respond manually, respond vocally, or listen passively to the correct response being spoken. A manual response was always required at test. In test blocks, the categories could either be novel or repeated from the learning block, whereas half of the stimuli were always novel and half were always repeated from the learning block. Because stimulus and category repetitions were manipulated orthogonally, it was possible to directly compare the relative contribution of S-R and C-R associations to performance. In Experiment 1, test performance was enhanced by repeating the C-R bindings independently of the stimulus. In Experiment 2, there was also evidence of an S-R repetition benefit independent of the classification. Critically, instructed associations formed in one response modality were robust to changes in the required response, even when no overt response was required during training, indicating the need to update the traditional view of associative learning

How Does the (Re)Presentation of Instructions Influence Their Implementation?

Instructions are so effective that they can sometimes affect performance beyond the instructed context. Such ‘automatic’ effects of instructions (AEI) have received much interest recently. It has been argued that AEI are restricted to relatively simple and specific S-R tasks or action plans. The present study put this idea further to the test. In a series of experiments based on the NEXT paradigm (Meiran, Pereg, Kessler, Cole, & Braver, 2015a) we investigated the specificity of AEI. In Experiment 1, we presented category-response instructions instead of S-R instructions. Nevertheless, we observed AEI for novel stimuli from the instructed category (Experiment 1a), and abstractness of the category did not modulate the size of the NEXT effect (Experiment 1b). However, Experiment 2 revealed specificity at the response level: AEI were much smaller in conditions where the instructed GO response is semantically related to, but procedurally different from the required NEXT response, compared to a condition where the NEXT and GO responses were the same. Combined, these findings indicate that AEI can occur when S(C)-R instructions are abstract at the stimulus level, arguing against previous proposals. However, AEI does seem to require specificity at the response level. We discuss implications for recent theories of instruction-based learning and AEI

Drug-microbiota interactions and treatment response: Relevance to rheumatoid arthritis

Knowledge about associations between changes in the structure and/or function of intestinal microbes (the microbiota) and the pathogenesis of various diseases is expanding. However, interactions between the intestinal microbiota and different pharmaceuticals and the impact of these on responses to treatment are less well studied. Several mechanisms are known by which drug-microbiota interactions can influence drug bioavailability, efficacy, and/or toxicity. This includes direct activation or inactivation of drugs by microbial enzymes which can enhance or reduce drug effectiveness. The extensive metabolic capabilities of the intestinal microbiota make it a hotspot for drug modification. However, drugs can also influence the microbiota profoundly and change the outcome of interactions with the host. Additionally, individual microbiota signatures are unique, leading to substantial variation in host responses to particular drugs. In this review, we describe several known and emerging examples of how drug-microbiota interactions influence the responses of patients to treatment for various diseases, including inflammatory bowel disease, type 2 diabetes and cancer. Focussing on rheumatoid arthritis (RA), a chronic inflammatory disease of the joints which has been linked with microbial dysbiosis, we propose mechanisms by which the intestinal microbiota may affect responses to treatment with methotrexate which are highly variable. Furthering our knowledge of this subject will eventually lead to the adoption of new treatment strategies incorporating microbiota signatures to predict or improve treatment outcomes

Spatial Attention in Task Switching

This thesis is a systematic investigation of preparatory reorienting of task-relevant spatial attention. Task switching experiments typically report a performance overhead when the current task is different to that performed on the previous trial relative to when the task repeats. This ‘switch cost’ tends to reduce as participants are given more time to prepare (consistent with an active reconfiguration process) but a ‘residual’ switch cost usually remains even at very long preparation intervals (often interpreted as evidence of carryover of response selection parameters from the previous trial which are immune to preparation). Although attentional selection of perceptual attributes is often considered to be part of task-set and is included in some models of task-set control, little research has investigated the dynamics of this component in detail. Over a series of seven experiments in which tasks were consistently mapped to screen locations, eye-tracking was used to systematically investigate task-relevant spatial selection of perceptual attributes during the preparation interval and early after stimulus onset. Experiment 1 revealed a switch-induced delay in appropriate attention orientation and a measure of ‘attentional inertia’ which could not be explained by task-independent re-orienting to locations or low-level oculomotor phenomena but were markers of task-relevant spatial selection. Experiment 2 provided a sensitive measure of both of these attentional handicaps and demonstrated that they both contribute to the switch cost (including its residual component). Although attentional inertia reduced with preparation, both handicaps were present at the longest preparation intervals. The constancy of the delay in attending to the relevant attribute reflects the effort to re-allocate attention, rather than peculiarities of spatial orienting when the cue and stimulus are presented near-simultaneously on trials with short cue-stimulus intervals. The presence of attentional inertia in blocks with long preparation intervals suggested some component of inertia immune to preparation (though see Experiments 5 and 6 below). Experiments 3 and 4 investigated the extent to which attentional selection can be decoupled from other task-set components. Cues which explicitly provided location information reduced (or eliminated) the attentional effects found in Experiment 2 indicating that attentional selection can be decoupled from other task-set components. However, Experiment 3 found that the ‘natural’ state is for attentional selection to be coupled at least to a degree (and accessed via) task-set. Experiment 5 combined eye-tracking with ERPs to investigate the relative order of attentional selection and reconfiguration of other task-set components. A well-documented ERP marker of task-set preparation always followed onset of the first fixation on the currently relevant stimulus element indicating that (at least some) task-set components are reconfigured in a serial order with spatial selection preceding other components (e.g., loading of S-R rules or other parameters into working memory). Experiments 6 and 7 investigated the nature of attentional inertia. In Experiment 6 participants were given ultimate control over the duration of the preparation interval which eliminated attentional inertia (at least as indexed by preferential fixation of the previously relevant element on switch trials). In Experiment 7 the stimulus comprised three items which were from perceptually distinct classes (digits, letters, objects) to investigate whether the presence of task-specific features would elicit extra attentional inertia and whether early spatial selection was effective enough to block the processing of task-irrelevant features once the stimulus was presented. Although there was some evidence that the previously relevant stimulus element ‘captured’ attention, this tendency was modest in the fixations and absent in performance measures (response congruence effects)

How Does the (Re)Presentation of Instructions Influence Their Implementation?

Instructions are so effective that they can sometimes affect performance beyond the instructed context. Such 'automatic' effects of instructions (AEI) have received much interest recently. It has been argued that AEI are restricted to relatively simple and specific S-R tasks or action plans. The present study put this idea further to the test. In a series of experiments based on the NEXT paradigm (Meiran, Pereg, Kessler, Cole, & Braver, 2015a) we investigated the specificity of AEI. In Experiment 1, we presented category-response instructions instead of S-R instructions. Nevertheless, we observed AEI for novel stimuli from the instructed category (Experiment 1a), and abstractness of the category did not modulate the size of the NEXT effect (Experiment 1b). However, Experiment 2 revealed specificity at the response level: AEI were much smaller in conditions where the instructed GO response is semantically related to, but procedurally different from the required NEXT response, compared to a condition where the NEXT and GO responses were the same. Combined, these findings indicate that AEI can occur when S(C)-R instructions are abstract at the stimulus level, arguing against previous proposals. However, AEI does seem to require specificity at the response level. We discuss implications for recent theories of instruction-based learning and AEI